CN116867415A - Medical device actuator - Google Patents

Abstract

A linkage assembly for a medical device may include: a rotatable member configured to rotate about a rotation axis; a piston; and a connecting rod rotatably connected to the rotatable member and the piston and movable along a range. The first end of the range may correspond to an initial position of the distal member movable by the linkage assembly and the second end of the range may correspond to a final position of the distal member. In a first configuration of the connecting rod, at a first end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis by a first amount, wherein the longitudinal axis is perpendicular to the rotational axis; in a second configuration of the connecting rod, at a second end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis by a second amount. The second amount may be less than two-thirds of the first amount.

Description

Medical device actuator

Technical Field

Aspects of the present disclosure relate generally to devices and methods for actuators of medical devices, and in particular, to actuators for components of a duodenal mirror (e.g., elevator levers).

Background

The duodenal mirror may include a handle and a sheath insertable into a body cavity of a subject. The sheath may terminate in a distal tip portion that may include features such as optical elements (e.g., camera, illumination), air/water outlets, and working channel openings. An elevator may be disposed at the distal tip and may be actuatable to change the orientation of the medical device/tool passing through the working channel. For example, the elevator may be pivotable or otherwise movable.

An element/actuator in the handle may control an element of the distal tip. For example, buttons, knobs, levers, etc. may control the elements of the distal tip. The elevator may be controlled by a control mechanism (e.g., a lever) in a handle that may be attached to a control line attached to the elevator. When the mechanism (e.g., lever) is actuated, the wire may move proximally and/or distally, thereby raising and/or lowering the elevator.

Disclosure of Invention

Each aspect disclosed herein may include one or more features described in connection with any other disclosed aspect.

In one example, a linkage assembly (linkage) for a medical device may include: a rotatable member configured to rotate about a rotation axis; a piston; and a connecting rod rotatably connected to the rotatable member and the piston and movable along a range. The first end of the range may correspond to an initial position of the distal member movable by the linkage assembly and the second end of the range may correspond to a final position of the distal member. In a first configuration of the connecting rod, at a first end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis by a first amount, wherein the longitudinal axis is perpendicular to the rotational axis. In a second configuration of the connecting rod, at a second end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis by a second amount. The second amount may be less than two-thirds of the first amount.

Any of the linkage assemblies disclosed herein may have any of the following features. One mechanical advantage of the linkage assembly may be that it may be at least 50% higher in the second configuration than in the first configuration. The first configuration may be located at the beginning of the travel of the linkage assembly. The second configuration may be at the end of travel of the linkage assembly. The rotatable member may be rotatable by a lever fixed to the rotatable member. The piston is operable to move a control wire coupled to the distal member. The distal member may be an elevator of the medical device. In the first configuration, the elevator may be in a fully lowered configuration. In the second configuration, the elevator may be in a fully raised configuration. The connecting rod may not be straight. The connecting rod may have a first section and a second section transverse to the first section. The connecting rod may also have a third section transverse to the second and first sections. The longitudinal axis may be coaxial with a diameter of the rotatable member extending through the rotational axis. The longitudinal axis may be substantially parallel or coaxial with a longitudinal axis defining movement of the plunger. In the first configuration, the proximal end of the lever may be offset from the longitudinal axis in a first direction by a first angle. In a second configuration, the proximal end of the lever may be offset from the longitudinal axis in the first direction by a second angle. The second angle may be greater than the first angle. The first angle and the second angle may each have an apex located at an intersection of the rotational axis and the longitudinal axis. The first edge of each of the first angle and the second angle may be defined by a line extending between the axis of rotation and the proximal end of the lever. The second of each of the first and second angles may be defined by a longitudinal axis. Edge(s)

In another example, the linkage assembly may include: a rotatable member configured to rotate about a rotation axis; a piston; and a connecting rod rotatably connected to the rotatable member and the piston and movable along a range. The first end of the range may correspond to an initial position of the distal member movable by the linkage assembly. The second end of the range may correspond to the final position of the distal member. In the first configuration of the connecting rod, at a first end of the range, the linkage assembly may have a first mechanical advantage. In the second configuration of the connecting rod, at a second end of the range, the linkage assembly may have a second mechanical advantage. The second mechanical advantage may be at least 50% higher than the first mechanical advantage.

Any of the linkage assemblies disclosed herein may have any of the following characteristics. In the first configuration, the proximal end of the lever may be offset from the longitudinal axis in a first direction by a first angle. In a second configuration, the proximal end of the lever may be offset from the longitudinal axis in the first direction by a second angle. The second angle may be greater than the first angle. The first angle and the second angle may each have an apex located at an intersection of the rotational axis and the longitudinal axis. The distal member may be an elevator of the medical device. In the first configuration, the elevator may have a lower yaw angle than in the second configuration.

In another example, a linkage assembly for a medical device may include: a connecting rod connected to the rotatable member of (a) and configured to rotate about an axis of rotation along a range. The first end of the range may correspond to an initial position of the distal member movable by the linkage assembly and the second end of the range may correspond to a final position of the distal member. The connecting rod may also be connected to (b) the piston. In a first configuration of the connecting rod, wherein the connecting rod is positioned at a first end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis, perpendicular to the rotational axis and extending through the rotational axis by a first amount. In a second configuration of the linkage assembly, wherein the connecting rod is positioned at a second end of the range, the proximal end of the connecting rod may be offset from the longitudinal axis by a second amount. The second amount may be less than two-thirds of the first amount. The mechanical advantage of the linkage assembly may be at least 50% higher in the second configuration than in the first configuration.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. In the case where the element is not circular, the term "diameter" may refer to the width. The term "distal" or "distal" refers to a direction away from an operator, and the term "proximal" or "proximal" refers to a direction toward an operator. The term "exemplary" refers to "example" rather than "ideal". The term "about" or similar terms (e.g., "substantially") include values of +/-10% of the specified value.

Brief description of the drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate aspects of the disclosure and together with the description, serve to explain the principles of the disclosure.

Fig. 1A and 1B depict aspects of an exemplary duodenum mirror.

Fig. 2A-4B depict an exemplary lever assembly.

Fig. 5A-5B are diagrams depicting aspects of the lever of fig. 2A-2B.

Fig. 6A-6B are diagrams depicting aspects of the lever of fig. 3A-4B.

Detailed Description

An actuator of a medical device (e.g., a lever of a duodenoscope) may require an operator to apply a large force to operate the actuator/lever in some configurations. For example, the lever may be used to raise and/or lower the elevator of the distal tip of the duodenal mirror. During surgery, an operator may use a lever when inserting a medical device into the working channel of the duodenal mirror in order to change the angle at which the medical device emerges from the distal end of the working channel. An operator may wish to use a lever to finely manipulate (fine-steer) the elevator in order to provide accurate positioning of the inserted medical device. When the angle of the elevator exceeds a certain angle (e.g., 60 degrees), the operator may be interested in fine maneuvers. Before reaching this particular angle (e.g., 60 degrees), the operator may not be concerned with fine manipulation of the elevator because a final position below this angle is undesirable.

The amount of force required to bend the elastic member (e.g., the flexible device/shaft held by the elevator) generally increases corresponding to the angle of deflection. When raising the elevator carrying the flexible means/shaft, the amount of force to raise the elevator by a given angular increment may increase with the elevator. For example, raising the elevator from 60 degrees to 70 degrees may require more force than raising the elevator from 50 degrees to 60 degrees. Such increased force may be consistent with the lift/bend angle of interest to the operator, as described above (e.g., an angle greater than 60 degrees). Articulation of the distal tip of the endoscope may result in a tortuous path of the control line of the elevator, generally increasing the amount of force required to raise the elevator over all of the range of the lever (e.g., over the entire range of the lever).

Accordingly, it may be desirable to reduce the amount of force required to raise and/or lower the elevator in order to enable an operator to perform a medical procedure. It may be particularly desirable to reduce the amount of force required to raise the elevator at an angle of interest (e.g., an angle greater than 60 degrees). The reduction in force may facilitate fine manipulation of the elevator to raise a medical tool (inserted into the endoscope and carried by the elevator) a particular desired amount. Further, it may be desirable to increase the speed of the elevator at lower angles (e.g., angles less than 60 degrees) in order to quickly move the elevator to the angular range of interest. It may be desirable for the elevator to move at a lower speed within the range of interest (e.g., above 60 degrees) in order to fine tune the position of the elevator.

As described in further detail below, the elevator lever assembly may include a rotatable member having a contact portion for contact by a user, a connecting rod rotatably coupled to the rotatable member, and a plunger rotatably coupled to the connecting rod. The components of the lever assembly may be selected such that lateral offset of the proximal end of the lever provides a mechanical advantage at higher angles of elevator motion. The lateral offset may be in a direction perpendicular to the longitudinal axis of the duodenal handle or the longitudinal axis of the components of the duodenal handle, (e.g., a longitudinal axis coaxial with the central axis of the plunger, or a longitudinal axis coaxial with the central axis of the rotatable member). The lateral offset at the relevant part of the range of contact portions (and thus of the elevator) provides a mechanical advantage at higher angles of elevator motion. The mechanical advantage may result in less force being required to raise the elevator at higher angles.

Although the term "duodenoscope" may be used herein, it should be understood that other devices (including, but not limited to, endoscopes, colonoscopes, ureteroscopes, bronchoscopes, laparoscopes, sheaths, catheters, or any other suitable delivery device or medical device, which may include an elevator or any other distal component that requires actuation or movement) may be used in conjunction with the devices and methods of manufacture of the present disclosure. While a side-facing device is specifically discussed, the embodiments described herein may also be used with a front-facing endoscope (e.g., an endoscope with a viewing element facing longitudinally forward). While the lever assembly described below is described as being used to raise/lower an elevator, it should be understood that the lever assembly may also be used to control other medical device components (e.g., steering or braking components).

Fig. 1A depicts an exemplary duodenal mirror 10 having a handle 12 and an insertion portion 14. Fig. 1B shows the proximal end of the handle 12. The duodenal mirror 10 may also include an umbilicus 16 for connecting the duodenal mirror 10 to sources such as air, water, suction, power, etc., as well as image processing and/or viewing equipment.

The insertion portion 14 may include a sheath or shaft 18 and a distal tip 20. The distal tip 20 may include an imaging device 22 (e.g., a camera) and a light source 24 (e.g., an LED or optical fiber). The distal tip 20 may be laterally oriented. That is, the imaging device 22 and the light source 24 may be radially outward, perpendicular, approximately perpendicular, or otherwise transverse to the longitudinal axis of the shaft 18 and the distal tip 20.

The distal tip 20 may also include an elevator 26 for changing the orientation of a tool inserted into the working channel of the duodenal mirror 10. The elevator 26 may alternatively be referred to as a swing bracket, a pivot bracket, a raised base, or any other suitable terminology. The elevator 26 may be pivotable via, for example, an actuation wire or another control element extending from the handle 12 through the shaft 18 to the elevator 26.

The distal portion of the shaft 18 connected to the distal tip 20 may have a steerable portion 28. The steerable portion 28 may be, for example, an articulating joint. The shaft 18 and the steerable portion 28 may comprise a variety of structures known or that may become known in the art.

The handle 12 may have one or more actuators/control mechanisms 30. The control mechanism 30 may provide control of the steerable portion 28 or may allow for the provision of air, water, suction, etc. For example, the handle 12 may include control knobs 32, 34 for left, right, up and/or down control of the steerable portion 28. For example, one of the knobs 32, 34 may provide left/right control of the steerable portion 28, and the other of the knobs 32, 34 may provide up/down control of the steerable portion 28. The handle 12 may also include one or more locking mechanisms 36 (e.g., knobs or levers) for preventing steering of the steerable portion 28 in at least one of an up, down, left, or right direction. The handle 12 may include an elevator control lever 38 (fig. 1B). Elevator control lever 38 may raise and/or lower elevator 26 via a connection between lever 38 and a wire.

Fig. 2A-4B illustrate an exemplary connection/linkage between the lever 38 and a line (not shown) extending from the lever 38 through the shaft 18 to the elevator 26. The port 40 may allow a tool to pass through the port 40 into the working channel of the duodenal scope 10, through the sheath 18, and to the distal tip 20.

In use, an operator may insert at least a portion of the shaft 18 into a body cavity of a subject. The distal tip 20 may be navigated to a surgical site in a body cavity. An operator may insert a tool (not shown) into port 40 and pass the tool through shaft 18 to distal tip 20 via the working channel. The tool may exit the working channel at the distal tip 20. The user may use the elevator control lever 38 to raise the elevator 26 and tilt the tool toward a desired location (e.g., nipple of the pancreatic biliary tract). The user may use the tool to perform a medical procedure.

Fig. 2A-4B depict an exemplary linkage assembly for use with the duodenal mirror 10. The linkage assembly of fig. 2A-4B may provide functionality to the elevator control lever 38 of fig. 1, providing a linkage for connecting the control lever 38 to a line for deflecting the elevator.

Fig. 2A and 2B illustrate an exemplary linkage assembly 100 in a first configuration (fig. 2A) and a second configuration (fig. 2B). The first configuration (fig. 2A) may correspond to the elevator being in an initial lowered (e.g., maximally, fully lowered) position. The second final configuration (fig. 2B) may correspond to the elevator being in an elevated (e.g., maximally, fully elevated) position.

The linkage assembly 100 may include a rotatable member 110, a connecting rod 120, and a plunger 130. The rotatable member 110 may include an elevator control lever 112, which may extend radially outward from an annular ring 114. The rotatable member 110 is rotatable about a central axis 115 of the annular ring 114. An annular ring 114 may be disposed within the handle 12 (fig. 1A-1B), and the elevator control lever 112 may extend outwardly (via, for example, a slit) through the housing of the handle 12. The edges of the slit may define the range over which the elevator control lever 112 is movable. Alternatively, other structures (e.g., cover 118) inside or outside the housing of handle 12 may limit the range in which elevator control lever 112 may move. The elevator control lever 112 may have a range extending from an initial position at one end of the range of the elevator control lever 112 to a final position at the other end of the range of the elevator control lever 112. The elevator control lever 112 may have any characteristic of the elevator control lever 38 (FIG. 1B). Elevator control lever 112 may include ridges for providing a contact surface for a user's finger and may provide traction to the user.

The annular ring 114 may rotate relative to the housing of the handle 12 such that movement of the elevator control lever 112 causes rotation of the annular ring 114 relative to the housing of the handle 12. The annular ring 114 and elevator control lever 112 may be a single unitary structure or may be attached to one another. The protrusion 116 may extend radially outward from the annular ring 114. As shown, the tab 116 may be a separate piece secured to the annular ring 114. Alternatively, the tab 116 may be integrally formed with the annular ring 114 and/or the control lever 112, or may be a separate piece.

The components of the rotatable member 110 may be formed of any suitable material. For example, the components of the rotatable member 110 may be formed of a rigid material, such as plastic or other polymers, composite materials, or metal. The control lever 112, annular ring 114 and tab 116 may be formed of the same material or different materials.

As shown in fig. 2A and 2B, a cover 118 may cover at least a portion of the annular ring 114. The cap 118 may provide separation between the annular ring 114 and other components of the handle 12 and/or may be used to maintain the annular ring 114 in a desired plane. The cover 118 is rotatable relative to the rotatable member 110 (including the annular ring 114). For example, the cover 118 may be stationary relative to the housing of the handle 12.

The proximal end of the connecting rod 120 may be secured to the protrusion 116, or to another portion of the rotatable member 110. For example, a pin may secure the connecting rod 120 to the protrusion 116 such that the connecting rod 120 may rotate relative to the protrusion 116. The connecting rod 120 may extend distally from the rotatable member 110 within the interior of the handle 12. As shown in fig. 2A and 2B, the connecting rod 120 may be straight. Alternatively, the connecting rod 120 may be curved and/or angled (see, e.g., fig. 4A and 4B). The distal end of the connecting rod 120 may be rotatably coupled to the plunger 130. For example, a pin or other structure may rotatably couple the distal end of the connecting rod 120 to the plunger 130. In fig. 2A and 2B, the proximal end of the plunger 130 may be covered by the distal end of the connecting rod 120. The connecting rod 120 may be formed of any suitable material. For example, the connecting rod 120 may be formed of a rigid material, such as plastic or other polymers, composite materials, or metal. The control lever 112, annular ring 114 and tab 116 may be formed of the same material or different materials.

The plunger 130 may extend generally parallel to the longitudinal axis of the handle 12. The distal end 132 of the plunger 130 may be coupled to a control line (not shown) that may be coupled to the elevator. As the plunger moves proximally and distally, the control wire may be pulled proximally or pushed distally, respectively. Such movement of the plunger and control line may cause the elevator to rise and/or fall. Plunger 130 may be formed of any suitable material. For example, the plunger 130 may be formed of a rigid material, such as plastic or other polymers, composite materials, or metal.

The movement of the plunger 130 may be constrained by the channel 140. The channel 140 may extend generally parallel to the longitudinal axis of the handle 12. The channel 140 may prevent movement of the plunger 130 in a direction perpendicular to the longitudinal axis and may constrain the plunger 130 from moving in the longitudinal direction. The control line may pass through the channel 140.

Various dimensions of the linkage assembly 100 are noted in fig. 2A and 2B. L1 refers to the length of the connecting rod 120 between its pivot points at the proximal and distal ends. As shown in fig. 2A and 2B, the connecting rod L1 in fig. 2A and 2B is the same because the connecting rod L1 may be rigid. θ1 may refer to the angle by which the proximal end of the connecting rod 120 rotates from the longitudinal axis LA, e.g., clockwise (the direction of the arrow in fig. 2A and 2B). The longitudinal axis LA may extend through the rotational axis 115 of the rotatable member 110. For example, the longitudinal axis LA may be coaxial with the diameter of the rotatable member 110. The longitudinal axis LA may be perpendicular to the rotational axis 115. The longitudinal axis LA may be parallel or coaxial with the longitudinal axis of the channel 140. The angles θ1 (a) (fig. 2A) and θ1 (B) (fig. 2B) may refer to values of θ1 in the configuration of fig. 2A (initial configuration of elevator descent) and the configuration of fig. 2B (final configuration of elevator elevation), respectively. θ1, θ1 (a), and θ1 (B) may each have an apex located at the intersection of the axis 115 and the longitudinal axis LA.

As shown in fig. 2A and 2B, the longitudinal axis LA may be coaxial with a central longitudinal axis of the channel 140. Alternatively, the longitudinal axis LA may be offset from the central longitudinal axis of the channel 140 (e.g., to the left or right of the central longitudinal axis of the channel 140 in fig. 2A and 2B). For example, the channel 140 may be offset in the left direction of fig. 2A and 2B relative to the longitudinal axis LA such that the channel 140 will intersect the path of the proximal end of the connecting rod 120 at a value of θ1 between 90 degrees and θ1 (B). Such a configuration may minimize frictional side loads when elevator 116 is within a range of interest (e.g., an angle greater than 60 degrees). The longitudinal axis LA may additionally or alternatively be parallel and/or coaxial with the longitudinal axis of the handle 12, as described above.

X1 represents the distance from the proximal end of the connecting rod 120 (at its pivot point) to the longitudinal axis LA of the handle 112, as described above. X1 (a) and X1 (B) refer to the value of X1 in the configuration of fig. 2A (initial configuration of elevator lowering) and the configuration of 2B (final configuration of elevator raising), respectively. X1 may be equal to Rsin (θ1).

In operation, the elevator may initially be in a lowered position (corresponding to the position of the linkage assembly shown in FIG. 2A). The rotation angle of the connecting rod 120 may have a value θ1 (a), which may correspond to the connecting rod lateral offset X1 (a). The plunger 130 may have a longitudinal position Y1 (a) corresponding to the lowered position of the elevator. The user may rotate the elevator control lever 112, thereby rotating the rotatable member 110 and moving the proximal end of the connecting rod 120. In the final raised position (corresponding to the position of the linkage assembly shown in fig. 2B), the angular value of rotation of the connecting rod 120 may be θ1 (B), which may correspond to the connecting rod lateral offset X1 (B). The plunger 130 may have a longitudinal position Y1 (B) corresponding to the raised position of the elevator.

When the rotatable member 110 rotates in the illustrated direction, the offset distance X1 changes. Fig. 5A is a graph depicting X1 values of different θ1 values. The horizontal axis reflects the value of θ1. The vertical axis reflects the value of X1. The value of X1 may be between-1 and 1. This is because X1 has been normalized to show a sinusoid. The actual value of X1 may vary and may reflect any suitable unit while preserving the shape of the curve, as described in detail below.

If the rotatable member 110 is capable of rotating a full 360 degrees, the value of X1 will vary between-1 and 1 in a sinusoidal pattern. But because the range of the rotatable member 110 may be limited (as described above, for example, the range of the control lever 112 may be limited by, for example, the edge of the housing of the handle 12 or the edge of the cover 118), only a portion of the sinusoidal curve may be traversed when the elevator control lever 112 is operated, resulting in rotation of the rotatable member 110. The solid curve 410 of FIG. 5A reflects how the lateral offset X1 varies within a typical usable range. The dashed curve of fig. 5A shows the portion of the sinusoidal curve that is not captured by the movement of the control lever 112/rotatable member 110 due to the limited range of the rotatable member 110 (or other portion of the linkage assembly 100).

θ1 (a) may be about 45 degrees and may reflect the value of θ1 when the elevator is in the initial lowered position. The leftmost end of the solid curve 410 may reflect the value of θ1 (A). θ1 (B) may be about 135 degrees and may reflect the value of θ1 when the elevator is in the raised position. The rightmost end of the solid curve 410 may reflect the value of θ1 (B). The rotatable member 110 (including the control lever 112) may thus be rotated approximately 90 degrees. The angle values provided above are merely exemplary. For example, the rotatable member 110 may range more or less than 90 degrees.

Referring to fig. 5A, as the control lever 112 rotates clockwise (as indicated by the arrow of fig. 2A) and the value of θ1 increases, the value of X1 first increases until θ1 is about 90 degrees. As the rotatable member 110 continues to rotate, the value of X1 then decreases. Because the range of values for θ1 may be approximately centered about 90 degrees, the value of X1 during rotation of the rotatable member 110 may be the top portion of the sinusoid described above.

The mechanical advantage of the linkage assembly 100 is plotted in fig. 5B. The mechanical advantage may be the ratio of the force generated by the linkage assembly 100 to the force applied to the linkage assembly 100. The higher mechanical advantage means that the force applied to the elevator control lever 112 is greater in multiple/magnification. The higher the mechanical advantage, the less force on the connecting rod is required to achieve the same movement of the elevator.

Fig. 5B illustrates the mechanical advantage of the linkage assembly 100 over the entire travel path of the rotatable member 110 in dashed curve 420. The dashed curve 420 in fig. 5B may cover the same rotation range as the solid line (X1 value) in fig. 5A. As shown in fig. 5B, the mechanical advantage (dashed curve 420) is inversely proportional to the value of X1 (solid curve 410). The mechanical advantage may be inversely proportional to the lever length (e.g., X1). The mechanical advantage of the linkage assembly 100 may be equal to the reciprocal of the lever length (1/X1). X1 may be equal to the distance from the rotational axis 115 to the proximal end of the connecting rod 120 (which may be about the same radius as the rotatable member 110) and may be equal to 1/(rsinθ1). As with the graph of X1 values (solid curve 410 of fig. 5A), the graph of values of mechanical advantage (dashed curve 420 of fig. 5B) may be approximately symmetrical. The mechanical advantage at θ1 (a) (initial lowered position of the elevator) and θ1 (B) (final raised position of the elevator) is about 1.4. When the rotatable member 110 rotates and the elevator is raised, the mechanical advantage first decreases to a value of about 1 and then increases again. The mechanical advantage (fig. 5B) is minimal when X1 (fig. 5A) is maximal (i.e., the value θ1=90°).

As described above, as the elevator is raised, the amount of force required to raise the elevator increases. The configuration of the rotatable member 110 provides a relatively modest level of mechanical advantage over the entire range of the elevator, including when the elevator is raised to the region of interest (where the operator may desire fine-tuning positioning).

Fig. 3A and 3B depict an alternative linkage assembly 200. The linkage assembly 200 may have any of the features of the linkage assembly 100, except as noted below. The linkage assembly 200 may provide greater mechanical advantage at a greater angle of the elevator than the linkage assembly 100 while maintaining the same change in elevator angle. This increased mechanical advantage may require less force to be applied to raise the elevator than the linkage assembly 100. Specifically, linkage assembly 200 may facilitate fine steering of the elevator at higher elevation levels of the elevator. Further, the speed of movement of the elevator of the linkage assembly 200 at higher angles may be less than that of the linkage assembly 100. The reduced speed may further facilitate accurate, fine-tuned maneuvers.

Fig. 3A and 3B illustrate the linkage assembly 200 in a first configuration (fig. 3A) and a second configuration (fig. 3B). The first configuration (fig. 3A) may correspond to an elevator in a lowered (e.g., fully/maximally lowered) position. The second configuration (fig. 3B) may correspond to the elevator being in an elevated (e.g., fully/maximally elevated) position.

The linkage assembly 200 may include a rotatable member 210, a connecting rod 220, and a plunger 230. The rotatable member 210, the connecting rod 220, and the plunger 230 may have any of the characteristics of the rotatable member 110, the connecting rod 120, and the plunger 130, respectively, unless otherwise specified herein. The rotatable member 210 may include an elevator control lever 212, which may have any of the characteristics of the elevator control lever 112. The length L2 of the connecting rod 220 may be the same as the length L1 of the connecting rod 120, or the lengths may be different. The plunger 230 may travel along the channel 240, and the channel 240 may have any of the characteristics of the channel 140.

The connecting rod 220 may be coupled to the rotatable member 210 at a different location as compared to the rotatable member 110 and the connecting rod 120. The protrusion 216 may have other locations on the rotatable member 210 as compared to the protrusion 116 of the rotatable member 110. The angle in the clockwise direction from the control lever 212 to the attachment location of the tab 216/connecting rod 220 may be less than the angle in the clockwise direction from the control lever 112 to the attachment location of the tab 116/connecting rod 120. In other words, in the lowered configuration of the elevator, the angular offset θ2 (a) of the proximal end of the connecting rod 220 relative to the longitudinal axis LA (described above with reference to fig. 2A) may be greater than the angular offset θ1 (a) of the connecting rod 120. And in the raised configuration of the elevator, the angular offset θ2 (B) of the proximal end of the connecting rod 220 relative to the longitudinal axis LA (as described above) may be greater than the angular offset θ1 (B) of the connecting rod 120. θ2, θ2 (a), and θ2 (B) may each have an apex at the intersection of the axis 115 (described above) and the longitudinal axis LA.

In operation, the elevator may initially be in a lowered position (corresponding to the position of linkage assembly 200 shown in FIG. 3A). The rotation angle of the connecting rod 320 may have a value θ2 (a), which may correspond to the connecting rod lateral offset X2 (a). The plunger 230 may have a longitudinal position Y2 (a) corresponding to the lowered position of the elevator. The user may rotate the elevator control lever 212, thereby rotating the rotatable member 210 to move the proximal end of the connecting rod 220. In the raised position (corresponding to the position of linkage assembly 200 shown in fig. 3B), the rotational angle of connecting rod 220 may have a value θ2 (B), which may correspond to the connecting rod lateral offset X2 (B). The plunger 230 may have a longitudinal position Y2 (B) corresponding to the raised position of the elevator.

In the lowered position of the elevator (fig. 2A, 3A), the offset X2 (a) of the connecting rod 220 may be greater than the offset X1 (a) of the connecting rod 120, and the angular offset θ2 (a) of the connecting rod 220 relative to the longitudinal axis LA may be greater than the angular offset θ1 (a) of the connecting rod 120. In the raised position of the elevator (fig. 2B, 3B), the offset X2 (B) of the connecting rod 220 may be less than the offset X1 (B) of the connecting rod 120, and the angular offset θ2 (B) of the connecting rod 220 relative to the longitudinal axis LA may be greater than the angular offset θ1 (B) of the connecting rod 120.

Fig. 6A shows a graph reflecting changes in values of θ2 and X2. The horizontal axis reflects the value of θ2. The vertical axis reflects the value of X2. The value of X2 may be between-1 and 1. This is because X2 has been normalized to show a sinusoid. The actual value of X2 may vary and may reflect any suitable unit. The shape of curve 510 (described in further detail below) may remain the same even though the values of X2 are different.

If the rotatable member 210 is capable of rotating a full 360 degrees, the value of X2 may vary between-1 and 1 in a sinusoidal pattern. But because the range of the rotatable member 210 may be limited (as described above, for example, the range of the control lever 212 may be limited, for example, by the edges of the housing of the handle 12 or the edges of the cover 118, as described with respect to fig. 2A and 2B), only a portion of the sinusoidal curve may be experienced during movement of the rotatable member 210. The solid curve 510 of fig. 6A reflects how the lateral offset X2 varies within the usable range. The dashed curve of fig. 6A illustrates a sinusoidal portion that is not achieved due to the limited range of rotatable member 210 (or other portion of linkage assembly 200).

θ2 (a) may be about 70 degrees and may reflect the value of θ2 when the elevator is in the lowered position. The leftmost end of the solid curve 510 may reflect the value of θ2 (a). θ2 (B) may be about 160 degrees and may reflect the value of θ2 when the elevator is in the raised position. The rightmost end of the solid curve 510 may reflect the value of θ2 (B). The rotatable member 210 (including the control lever 212) may thus be rotated approximately 90 degrees. The angle values provided above are merely exemplary. For example, the rotatable member 210 may range more or less than 90 degrees.

Compared to the solid curve 410 (fig. 5A) of the value of X1, it should be appreciated that the solid curve 510 (fig. 6A) of the value of X2 is shifted horizontally to the right by an amount equal to the difference between θ2 (a) and θ1 (a). In other words, the portion of the sinusoid captured by the motion of rotatable member 210 (solid curve 510) moves to the right relative to the portion of the sinusoid captured by the motion of rotatable member 110 (solid curve 410). The value of X1 (FIG. 5A, which relates to linkage assembly 100) corresponds to the top of the sinusoidal curve, being approximately symmetrical. In contrast, the value of X2 (FIG. 5B, which relates to linkage assembly 200) is asymmetric.

As the control lever 212 is actuated, causing the rotatable member 210 to rotate clockwise (as indicated by the arrows in fig. 3A and 3B), X2 changes as indicated by the solid line 510 in fig. 6A. In the initial phase (when the elevator is at a lower angle), X2 increases slightly along the sinusoid before reaching a peak (e.g., at a value of θ2 of 90 degrees). Then X2 decreases along the sinusoidal curve. As described above, the graph of X2 values (solid curve 510 of fig. 6A) is asymmetric such that the portion of solid curve 510 to the right of the peak of solid curve 510 is larger than the portion of solid curve 510 to the left of the peak of solid curve 510. For example, the portion of the solid curve 510 to the left of the peak (at a rotation angle θ2 of 90 degrees) may be about 15% -30% of the total curve.

As shown in fig. 6A, the value of X2 (e.g., X2 (a)) at the beginning of the stroke of the linkage system 200 may be slightly less than 1 (e.g., about 0.8 to about 1.0, or more specifically about 0.85 to about 0.95), on the scale of fig. 6A. The X2 value (e.g., X2 (B)) at the end of travel of the linkage system 200 may be less than 0.5 (e.g., about 0.25 to about 0.5, or about 0.30 to about 0.40).

The mechanical advantage of linkage assembly 200 is plotted in fig. 6B. The mechanical advantage may be the ratio of the force generated by the linkage assembly 200 to the force applied to the linkage assembly 200. The higher mechanical advantage means a greater multiple/magnification of the force applied to the lever 212. The higher the mechanical advantage, the less force on the connecting rod is required to achieve the same movement of the elevator as when the mechanical advantage is lower.

Fig. 6B illustrates the mechanical advantage of linkage assembly 200 over the entire travel path of rotatable member 210 in dashed curve 520. The dashed curve 520 in fig. 6B may cover the same rotation range as the solid line 510 (X2 value) in fig. 6A. As shown in fig. 6B, and as discussed above with respect to fig. 6A, the mechanical advantage (dashed curve 520) is inversely proportional to the value of X2.

The mechanical advantage is just greater than 1 (e.g., about 1.0-1.1) at θ2 (a) (lowered position of elevator). The mechanical advantage at θ2 (B) (the raised position of the elevator) is about 3. As the rotatable member 210 rotates and the elevator rises, the mechanical advantage first decreases slightly to a value of about 1 and then increases again. The mechanical benefit (fig. 6B) is smallest when X2 (fig. 6A) is largest (its value is θ2=90° (i.e., θ2 (B)).

As described above, as the elevator is raised, the amount of force required to raise the elevator increases. The configuration of the linkage assembly 200 creates increased mechanical advantage as the elevator is raised to a higher level. This mechanical advantage counteracts or at least partially counteracts the increased force required to raise the elevator at higher angles. For example, a value of θ2 between about 140 degrees and about 160 degrees (e.g., between 145 degrees and about 155 degrees) may correspond to a range of elevator inclinations of particular interest to the operator. This angular range corresponds to a mechanical advantage of about 1.56 to about 2.92 (e.g., about 1.74 to about 2.36).

At the beginning of the travel of the linkage assembly 200 (the configuration of fig. 3A), the mechanical advantage of the linkage assembly 200 may be slightly greater than 1 (e.g., between about 1.0 and about 1.5, or more specifically between 1.01 and 1.15). At the end of travel of the linkage assembly 200 (the configuration of fig. 3B), the mechanical advantage of the linkage assembly 200 may be about 3, such that the mechanical advantage increases by about 300% throughout the travel. Alternatively, the mechanical advantage of the linkage assembly 200 at the end of the stroke may be higher or lower (e.g., may be at least about 1.5, at most about 10, or some other value).

As shown in fig. 6B, and as indicated above, the mechanical advantage at the end of travel (fig. 3B) of the linkage assembly 200 may be at least 50% higher than the mechanical advantage at the beginning of travel (fig. 3A). Alternatively, the mechanical advantage of linkage assembly 200 at the end of travel (FIG. 3B) may be at least 175% or 300% higher than the mechanical advantage at the beginning of travel (FIG. 3A). This relationship between mechanical advantage at the beginning of the stroke and mechanical advantage at the end of the stroke may facilitate the use of less force to raise the elevator to a higher deflection level and may facilitate fine manipulation of the elevator at the deflection level of interest. An increase in mechanical advantage of at least 50% may correspond to a linkage assembly in which the offset value (e.g., X2 (B)) of the connecting rod 220 at the end of the stroke is less than two-thirds of the offset value (e.g., X2 (a)) of the connecting rod 220 at the beginning of the stroke. When X2 (B) is two-thirds of X2 (A), the mechanical advantage (reciprocal of the two-thirds) may be 150%. For example, as shown in fig. 6A, X2 (B) is about half of X2 (a).

For example, the linkage assembly 200 requires much less force to raise the elevator at a higher angle than the linkage assembly 100. The reduction in force facilitates the ability of the user to fine tune the elevator angle to accurately position the medical device delivered along the working channel. Further, the configuration of linkage assembly 200 results in higher speed movement of the elevator at lower angles and lower speed movement of the elevator at higher angles. The user can quickly move the elevator to the lower end of the range of interest and then benefit from the reduced speed to more easily fine tune the positioning at the angle of interest.

Fig. 4A and 4B depict another example linkage assembly 300. In fig. 4A, the linkage assembly 300 is in a lowered configuration (e.g., a fully/maximally lowered configuration). In fig. 4B, the linkage assembly 300 is in a raised (e.g., fully/maximally raised) configuration. The linkage assembly 300 may have any of the characteristics of the linkage assembly 100 or, in particular, the linkage assembly 200. The linkage assembly 300 may have the same characteristics as the linkage assembly 200 unless specified below.

The linkage assembly 300 may have a connecting rod 320. The connecting rod 320 differs from the connecting rod 220 in that the connecting rod 320 has an angled (nonlinear) shape, as described below. Although the connection rod 320 has a different shape from the connection rod 220, the connection rod has the same length as the connection rod 220 such that l3=l2. The connecting rod 320 may also be coupled to the rotatable member 210 at the same location that the connecting rod 220 is coupled to the rotatable member 210. Thus, the diagrams of FIGS. 6A-6B are equally applicable to the linkage assembly 300 as they are to the linkage assembly 200, and the linkage assembly 300 has the advantage of the linkage assembly 200 in terms of mechanical advantage and other characteristics.

The connecting rod 320 may follow a zig-zag (non-linear) pattern or geometry. The connecting rod 320 may include three or more segments 322, 324, and 326, each of which may be transverse to each other. Segment 324 may be disposed between segments 322 and 326. The interior angle between segments 322 and 324 may be smaller or larger than the interior angle between segments 324 and 326. Both internal corners may be obtuse. Segments 322 and 326 may have substantially the same length. Segment 324 may be longer or shorter than either of segments 322 and 326. As shown in fig. 4A, segments 322, 324, and 326 may be connected at a circular joint.

The shape of the connecting rod 320 may be selected to avoid interference with other components of the handle 12. The connecting rod 320 may be free to move when the elevator control lever 212 is actuated without interfering with or by other components of the handle 12. The shape of the connecting rod 320 shown in fig. 4A and 4B is merely exemplary. Any suitable shape may be selected to avoid interference between the connecting rod 320 and other components of the handle.

While the principles of the present disclosure are described herein with reference to illustrative examples for particular applications, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art with access to the teachings provided herein will recognize additional modifications, applications, and alternatives to the equivalents, which would be within the scope of the examples described herein. Accordingly, the invention is not to be seen as limited by the foregoing description.

Claims (15)

1. A linkage assembly for a medical device, the linkage assembly comprising:

a rotatable member configured to rotate about a rotation axis;

a piston; and

a connecting rod rotatably connected to the rotatable member and the piston and movable along a range, wherein a first end of the range corresponds to an initial position of a distal member movable by a linkage assembly and a second end of the range corresponds to a final position of the distal member, wherein:

in a first configuration of the connecting rod, at a first end of the range, a proximal end of the connecting rod is offset from a longitudinal axis by a first amount, wherein the longitudinal axis is perpendicular to the rotational axis; and

in a second configuration of the connecting rod, at a second end of the range, a proximal end of the connecting rod is offset from the longitudinal axis by a second amount, wherein the second amount is less than two-thirds of the first amount.

2. The linkage assembly of claim 1 wherein the mechanical advantage of the linkage assembly is at least 50% higher in the second configuration than in the first configuration.

3. A linkage assembly according to any preceding claim, wherein the first formation is located at the start of travel of the linkage assembly.

4. A linkage assembly according to claim 3, wherein the second formation is located at the end of travel of the linkage assembly.

5. A linkage assembly according to any one of the preceding claims, wherein the rotatable member is rotatable by a lever fixed to the rotatable member.

6. A linkage assembly according to any one of the preceding claims, wherein the piston is operable to move a control wire coupled to the distal member.

7. A linkage assembly according to any one of the preceding claims, wherein the distal member is an elevator of the medical device.

8. The linkage assembly of claim 7 wherein in the first configuration the elevator is in a fully lowered configuration and wherein in the second configuration the elevator is in a fully raised configuration.

9. A linkage assembly according to any one of the preceding claims, wherein the connecting rod is not straight.

10. The linkage assembly of claim 9 wherein the connecting rod has a first section and a second section transverse to the first section.

11. The linkage assembly of claim 10 wherein the connecting rod further has a third section transverse to the second section and the first section.

12. A linkage assembly according to any one of the preceding claims, wherein the longitudinal axis is coaxial with a diameter of the rotatable member extending through the rotational axis.

13. A linkage assembly according to any one of the preceding claims, wherein the longitudinal axis is substantially parallel or coaxial to a longitudinal axis defining movement of the plunger.

14. A linkage assembly according to any one of the preceding claims, wherein in the first configuration the proximal end of the lever is offset from the longitudinal axis by a first angle in a first direction, wherein in the second configuration the proximal end of the lever is offset from the longitudinal axis by a second angle in the first direction, and wherein the second angle is greater than the first angle, and wherein the first and second angles each have an apex at the intersection of the rotational axis and the longitudinal axis.

15. The linkage assembly of claim 14, wherein the first and second angles are each defined by a line extending between the rotational axis and a proximal end of the lever, and wherein the first and second angles are each defined by the longitudinal axis.